The GFPT is 20 hours minimum, not 40 (if minimum is what you meant in your post). Five of the those twenty hours must be solo. PPL is 40 hours minimum, of which 10 must be solo. That 40 hours includes GFPT time.
Note that the GFPT is an optional test on the way to a PPL. Most people do it because it removes or reduces some of the limitations but it's not a requirement. Another advantage is that items tested during the GFPT don't have to be tested on the PPL flight test. Without a GFPT *everything* has to be done on the PPL test.
Of course I've quoted minimum allowable time & most people take something more than that. How much more depends on the student's aptitude, study amount, age, frequency of training & weather, amongst other things. Can't do much about your age, but being well prepared & flying more frequently - especially in the early stages - in weather that's appropriate for the stage of training will tend to reduce the overall time to reach a standard of skill.